swap: use swapon -o

This patch simplify swapon usage in systemd. The command swapon(8)
since util-linux v2.26 supports "-o <list>". The idea is exactly the
same like for mount(8). The -o specifies options in fstab-compatible
way. For systemd it means that it does not have to care about things
like "discard" or another swapon specific options.

        swapon -o <options-from-fstab>

For backward compatibility the code cares about "Priority:" swap unit
field (for a case when Priority: is set, but pri= in the Options: is
missing).

References: http://lists.freedesktop.org/archives/systemd-devel/2014-October/023576.html
This commit is contained in:
Karel Zak 2015-05-25 12:11:23 +02:00 committed by Tom Gundersen
parent 49f582c0a0
commit bf1d7ba70a
4 changed files with 26 additions and 50 deletions

2
README
View File

@ -136,7 +136,7 @@ REQUIREMENTS:
During runtime, you need the following additional
dependencies:
util-linux >= v2.25 required
util-linux >= v2.26 required
dbus >= 1.4.0 (strictly speaking optional, but recommended)
dracut (optional)
PolicyKit (optional)

View File

@ -177,7 +177,8 @@
<listitem><para>Swap priority to use when activating the swap
device or file. This takes an integer. This setting is
optional.</para></listitem>
optional and ignored when priotiry is set by <option>pri=</option> in the
<varname>Options=</varname> option.</para></listitem>
</varlistentry>
<varlistentry>

View File

@ -717,8 +717,8 @@ fail:
}
static void swap_enter_activating(Swap *s) {
_cleanup_free_ char *discard = NULL;
int r, priority = -1;
_cleanup_free_ char *opts = NULL;
int r;
assert(s);
@ -726,13 +726,21 @@ static void swap_enter_activating(Swap *s) {
s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
if (s->from_fragment) {
fstab_filter_options(s->parameters_fragment.options, "discard\0", NULL, &discard, NULL);
int priority = -1;
priority = s->parameters_fragment.priority;
if (priority < 0) {
r = fstab_find_pri(s->parameters_fragment.options, &priority);
r = fstab_find_pri(s->parameters_fragment.options, &priority);
if (r < 0)
log_warning_errno(r, "Failed to parse swap priority \"%s\", ignoring: %m", s->parameters_fragment.options);
else if (r == 1 && s->parameters_fragment.priority >= 0)
log_warning("Duplicate swap priority configuration by Priority and Options fields.");
if (r <= 0 && s->parameters_fragment.priority >= 0) {
if (s->parameters_fragment.options)
r = asprintf(&opts, "%s,pri=%i", s->parameters_fragment.options, s->parameters_fragment.priority);
else
r = asprintf(&opts, "pri=%i", s->parameters_fragment.priority);
if (r < 0)
log_notice_errno(r, "Failed to parse swap priority \"%s\", ignoring: %m", s->parameters_fragment.options);
goto fail;
}
}
@ -740,24 +748,9 @@ static void swap_enter_activating(Swap *s) {
if (r < 0)
goto fail;
if (priority >= 0) {
char p[DECIMAL_STR_MAX(int)];
sprintf(p, "%i", priority);
r = exec_command_append(s->control_command, "-p", p, NULL);
if (r < 0)
goto fail;
}
if (discard && !streq(discard, "none")) {
const char *discard_arg;
if (streq(discard, "all"))
discard_arg = "--discard";
else
discard_arg = strjoina("--discard=", discard);
r = exec_command_append(s->control_command, discard_arg, NULL);
if (s->parameters_fragment.options || opts) {
r = exec_command_append(s->control_command, "-o",
opts ? : s->parameters_fragment.options, NULL);
if (r < 0)
goto fail;
}

View File

@ -53,10 +53,9 @@ static int add_swap(
bool noauto,
bool nofail) {
_cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL, *filtered = NULL;
_cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r, pri = -1;
const char *opts;
int r;
assert(what);
assert(me);
@ -71,18 +70,6 @@ static int add_swap(
return 0;
}
opts = me->mnt_opts;
r = fstab_find_pri(opts, &pri);
if (r < 0) {
log_error_errno(r, "Failed to parse priority, ignoring: %m");
/* Remove invalid pri field */
r = fstab_filter_options(opts, "pri\0", NULL, NULL, &filtered);
if (r < 0)
return log_error_errno(r, "Failed to parse options: %m");
opts = filtered;
}
r = unit_name_from_path(what, ".swap", &name);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
@ -109,20 +96,15 @@ static int add_swap(
"What=%s\n",
what);
/* Note that we currently pass the priority field twice, once
* in Priority=, and once in Options= */
if (pri >= 0)
fprintf(f, "Priority=%i\n", pri);
if (!isempty(opts) && !streq(opts, "defaults"))
fprintf(f, "Options=%s\n", opts);
if (!isempty(me->mnt_opts) && !streq(me->mnt_opts, "defaults"))
fprintf(f, "Options=%s\n", me->mnt_opts);
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write unit file %s: %m", unit);
/* use what as where, to have a nicer error message */
r = generator_write_timeouts(arg_dest, what, what, opts, NULL);
r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
if (r < 0)
return r;